Carbon/carbon (“C/C”) parts are employed in various industries. C/C parts may be used as, for example, friction disks such as aircraft brake disks, race car brake disks, clutch disks, and the like. C/C brake disks are especially useful in such applications because of the superior high temperature characteristics of C/C material. In particular, the C/C material used in CC parts is a good conductor of heat, and thus is able to dissipate heat away from the braking surfaces that is generated in response to braking. C/C material is also highly resistant to heat damage, and is capable of sustaining friction between brake surfaces during severe braking, without a significant reduction in the friction coefficient or mechanical failure. Ceramic Matrix Composites (CMCs) exhibit useful thermal and mechanical properties and hold the promise of being outstanding materials for use in high temperature environments and/or in heat sink applications. Ceramic Matrix Composites generally comprise one or more ceramic materials disposed on or within another material, such as, for example, a ceramic material disposed within a structure comprised of a fibrous material. Fibrous materials, such as carbon fiber, may be formed into fibrous structures suitable for this purpose.
C/C material and/or CMCs are generally formed using a precursor fiber, such as continuous oxidized polyacrylonitrile (PAN) fibers, referred to as “OFF” fibers. OPF fibers are precursors of carbonized PAN fibers and are used to fabricate a preformed shape, formed by, for example, laying out fiber tows along several fiber orientations followed by a series of needling steps. Typically, two or more layers of fibers are layered onto a support and are then needled together simultaneously or in a series of needling steps. This process interconnects the horizontal fibers with a third direction also called the z-direction, and the fibers extending into the third direction are also called z-fibers. This needling process may involve driving a multitude of barbed needles into the fibrous layers to displace a portion of the horizontal fibers into the z-direction.
One current approach used to prepare fibrous preform structures for manufacturing carbon-carbon brake disks is to needle punch layers of OPF fibers in a board shape from which donut shape preforms may be cut. The preforms are subsequently subjected to a costly carbonization cycle to transform the fibers into carbon. This approach yields a large amount of fiber waste and has limitations in fiber selection and fiber architecture designs. A more effective method to fabricate the fibrous preform structure is to organize carbonized fibers in a continuous handleable helically formed fabric prepared with a suitable fiber architecture. The helical carbon fiber fabric is subsequently fed into a circular needle punch machine to prepare a near net shape three dimensional textile. The various carbon fiber tows of the fabric may be interlaced using weaving.
Weaving typically yields fabrics with undesired fiber crimp levels in both warp and weft directions, especially in a weave pattern such as plain weave. For a given weave pattern and tow size, the amount of crimp increases with the areal weight of the fabric. The crimp present in the starting fabric degrades the in plane mechanical and thermal properties of the finished carbon carbon composite. Accordingly, there is a need for developing systems and methods for the production of fabrics exhibiting reduced crimp.